smyth



(No Model.)

D. M. SMYTH.

Book Sewing.-

No. 238,451.. "Patented March 1, I881.

N PETERS, FNOTO-LITHOBRAPHER, WASHINGLON, n c.

UNITED STATES rena Charon;

DAVID M. SMYTH, OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE SMYTHMANUFACTURING COMPANY, OF SAME PLACE.

BOOK-SEWING.

SPECIFICATION forming part of Letters Patent No. 238,451, dated March 1,1881.

Application filed December 27, 1880.

To all whom it may concern:

Be it known that I, DAVID M. SMYTH, of Hartford, in the county ofHartford and State of Connecticut, haveinvented an Improvement inBook-Sewing, of which the following is a specification.

The present invention is an improvement in the method of sewing booksand in the sewed book the sheets of which are held together by mypeculiar sewing.

The object of this invention is to render the sewing partially elastic,so that strain at one part of the book may be transferred to otherthreads besides the particular threads that hold the leaves upon whichthe strain comes. By this improvement the threads are more durable andthe binding stronger.

I make use of double threads that pass from opposite directions throughbetween the folds of different sheets and are interlocked by a row ofloops, somewhat similar to the chainstitch in sewing. ing elastic wherethe threads are looped together.

My book-sewin g machine represented in Letters Patent No. 220,312,October 7,1879, is capable of performing the sewing according to mypresent invention, if the parts are timed to move in the mannerhereinafter set forth.

In the accompanying diagram, Figure 1 represents the backs of the foldedsheets, ready to receive the sewing, and Fig. 2 is a representation ofthe manner in which the threads are interlooped.

Presuming that curved needles are employed, as shown in said patent, itis to be understood that the needle to is to pass through the foldedsheet 11, carrying with it a loop of thread, 6, and the point of theneedle to emerges at the saw-cut c, and a looper takes a loop of saidthread and holds it. The needle (1 now enters the next sheet, 0, in theopposite direction, and, passing out at the saw-cut 0, goes through theloop of thread 6. The looper moves and drops the loop 6 over the needle(I, and the thread is drawn up by the take-up. The looper then goesforward and takes loop from the needle (I, after which said needle drawsback, leaving a loop of the threadz'around the looper. The needle tothen enters the next sheet, f, and

This renders the line of sew (No model.)

passing out takes the loop of needle-thread ifrom the looper. Saidneedle retires, leaving its loop 2', and then said needle d enters thesheetg, and passes into the loop of thread 6, and so on. By this mode ofsewing the double 5 5 threads, passing through the folds of the sheetsin opposite directions, will be looped together in the manner indicatedat an as, Fig. 2, forming an elastic line of interlocked stitches. Wherethe threads 6 and 'i enter and leave the folds of the sheets the saidsheets should be sawed,

as at M2, and the threads will pass in these saw-cuts from one sheet tothe next. It is, however, preferable to employ cords for the threads topass around, as at n and 0, said cords being drawn by the threads intothe grooves. It is, however, necessary to make use of means for movingsuch cords, as set forth in my said patent, so that the needle at onestitch may pass one side of the cord and at the next stitch on the otherside of the cord,

so that the threads may go around such cords,

as shown in the drawings.

I have only shown one line of the double stitching with the twothreadspassing from 7 opposite directions and interlocked. It is, however, tobe understood that the book may be sewed with two, three, or more suchlines of double stitching, there being two needles for each line ofdouble stitching.

' A cord may be laid in the groove 0 as the sewing progresses, ifdesired; or a needle may occupy the lower part of said groove, by whichthe cord will afterward be drawn in the groove, and the cord will bebetween the interlocked 8 loops and the folded sheets.

It will also be evident that a strip of parchment or other material, t,may be between the interlocked loops and the folds of the sheets, eitherin the groove 0 or behind the folds of the sheets, and that therespective loops may emerge from the folds of the sheets at sufficientdistances apart for the introduction of such strip.

It is to be understood that the looper is to be moved by suitablemechanism, and this will probably form the subject of a separateapplication.

I claim as my invention- 1. The method herein specified of sewing :00

folded sheets together to form books, consistin g in passing a doublethread through at the back of the sheet, passing a second double threadthrough at the back of the next sheet and in the opposite direction andthrough the loop of the first thread, then passing the first threadthrough at the back of another sheet and through the loop ofthe secondthread, and so on, substantially as set forth.

2. A book in which the folded sheets are connected at the back by twothreads passing double and from opposite directions through the backs ofthe sheets, and connected by interlocking loops, substantially as setforth.

DAVID M. SMYTH.

Witnesses:

G120. T. PINOKNEY, OI-IAs. E. SMITH.

